Oil well heater



Get. 23, 1956 E. H. KRAMER OIL WELL HEATER Filed Deo. 21, 1953 INVENTOR.5A. Kramer Arron/VES United States Patent O OIL WELL HEATER Earnest H.Kramer, Tulsa, Okla., assignor of one-half to Robert P. Lair, Tulsa,Okla.

Application December 21, 1953, Serial No. 399,388 Claims.. (Cl. 166-61)This invention relates to improvements in toil well heaters, and moreparticularly, but not by way of limitation, to an improved gasl typeheater adapted for disposal in the lower portion of a producing oilwell.

A large percentage of the present day oil wells produce a well liquidcontaining parain or having an asphalt base. Either of these types ofoil, and particularly the oil containing paratlin, tends to partiallysolidify as the oil is pumped. Y When the oil enters the pumping unitthe parain enters the working parts of the pump and often renders thevalve elements inoperable inV a very short time. In some wells, theparaffin will also tend to solidify in the welltubing above the pumpingunit and interfere with the ilow of the pumped uid to the surface.

The present invention contemplates a novel heater which may be disposedbelow the pumping unit to heat the oil being drawn into the pumping unitfrom the oil producing strata. The heater is simple in construction andvutilizes a section of tubing depending from the pumping unit as aportion of the heater to provide a thorough and efficient heating of theincoming well fluid. Furthermore, the heater dissipates a portion of itsheat outwardly into the oil producing strata to enhance the recovery ofoil therefrom. If the pumping unit is operating properly, but the paranis solidifying above the pumping unit, the present heater may beinterposed in the tubing string above the pump and retain the pumpedfluid in a liquid state.

An important object of this invention is to prevent paraiin fromclogging or jamming the bottom hole oil well pumping unit, or the tubingcontaining the pumped well fluid.

Another object of this invention is to heat the oil producing strata'inthe vicinity of an oil well and enhance the recovery of oil therefrom.

Another object of `this invention is to provide a simple and efncientheater for disposal in the lower portion of an oil well bore whichutilizes a section of the well tubing as an element of the heater andwhich may be economically manufactured.

A further object of this invention is to heat the Well fluid of aproducing oil Well prior to the entrance of the well uid into a bottomhole pumping unit.

A still further object of this invention is to provide an oil wellheater for disposal in the well tubing string which may be operated fromthe surface and operated only when desired.

Other objects and adavntages of the invention will be evident from thefollowing detailed description, read in conjunction with theaccompanying drawings, which illustrate my invention.

In the drawings:

Figure 1 is a vertical sectional view, partially in elevation, of mynovel heater installed in an oil well.

Figure 2 is a transverse sectional view of the heater as taken alonglines 2--2 of Fig. 1.

Referring to the drawings in detail, reference character 2 designatesthe usual well casing which extends downwardlyk in the well bore to theproducing strata (not Tice shown). Suspended concentrically in the wellcasing 2 1s the usual well tubing 4 which interconnects the bottom holepumping unit (not shown) with the surface equipment (not shown).

A tubular jacket 6, having its opposite ends 8 bent inwardly into closecontact with a section 10 of the tubing 4, is welded or otherwiserigidly secured on the tubing section 10 to form a closed annularchamber 12 around a portion of the tubing section 10. The chamber 12 isprovided to receive combustible gas which is supplied thereto through asmall tubing 14 from the surface of the well. An ordinary air regulator16 is secured in the side wall of the inner jacket or housing 6 toreceive the lower end :of the gas tubing 14 and control the air-fuelratio in a Well known manner. A plurality of vertically spaced apertures18 are formed transversely in the side wall ofy the jacket 6 throughoutsubstantially the entire length thereof to discharge the gas mixturefrom the chamber 12. Although only one vertical row of apertures isshown,'it is preferred that two or more circumferentially spaced rowsare formed in the jacket 6 to provide a discharge of the gas from thechamber 12 in various directions.

An outer sectional jacket 2i) is disposed around the inner jacket 6 andthe tubing section 10 to form a closed substantially annular shapedchamber 22. The upper section 24 of the housing or jacket 20 has itsupper end 26 enclosed and welded or otherwise rigidly secured to thetubing section 10' slightly above the upper end of the inner jacket 6'.A small aperture 23 is provided in the upper end 26 to receive the gastubing 14. Another and larger aperture 30 is also provided in the upperend 26 ofthe housing section 24 to receive a flue pipe 32. The flue pipe32 extends upwardly from the outer jacket 20 through a suitable packer(not shown) to provide an escape of exhaust fumes or gases from thechamber 22 and supply fresh air for the regulator 16 in such a manner tominimize air currents in the chamber 22. It will also be apparent thatthe ue pipe 32 may extend upwardly to the surface of the well in theevent it is not feasible to install a packer above the outer jacket 20,and may be provided with the usual ilue cap 34. It will also beunderstood that more than one flue pipe 32 may be provided, dependingupon the size of the chamber 22 and rate of combustion therein.

The lower section 36 of the outer jacket 20 is threadedly secured to theupper section 24 by means of a suitable collar or coupling 38. lThelower section 36 extends downwardly beyond the lower end of the innerjacket 6 and is reduced in diameter at its lower end 40 to enter acoupling member 42 which is threadedly secured on the lower end of thetubing section 10. An upwardly extendingcircumferential flange 44 isprovided` onthe upper end of the coupling 42 to tightly receive thelower end portion40 of the jacket section 36. Cooperating taperedsurfaces 46 may be formed on the outer periphery of the jacket end 40and the inner periphery of the flange 44 to provide a substantially gastight fit of the jacket 20 in the coupling 42, if desired. Also, asuitable gasket 48 may be disposed in the coupling 42 on an upwardlyfacing circumferential shoulder 50 to receive the lower end of thejacket'20 and enhance the seal of the jacket 20 around the tubingsection 10. VAnother section 52 of the tubing string 4 may be Vthreadedinto the coupling 42, depending upon the height of the outer jacket 2i)with respect to the bottom hole pumping unit, as will be hereinafter setforth.

` As previously stated, the chamber 22 provides a combustion chamber forthe gas mixture discharging through the apertures 18. A suitable igniter54 is supported in the outer jacket 20 and extends transversely throughthe chamber 22 into proximity with the inner jacket 6 and substantiallyin alignment with one of the rows of apertures 18. Although only oneigniter 54 is shown, one is preferably provided for each row ofapertures 18. Each igniter 54 is bolted or otherwise rigidly secured tothe jacket 20 in such a manner to provide a seal around the igniter S4and prevent a leakage of fumes or Well fluid through the jacket 20. Aninsulated electrical lead line 56 interconnects with each igniter 54outwardly of the jacket 20 and extends upwardly through the well casing2 to the surface. As shown in Fig. l, the lead line 56 may extend intothe flue pipe 32 upwardly of the outer jacket 20, if desired. Also, thegas tubing 14 may ne inserted in one of the ue pipes 32, whereby theflue pipes will provide housings for the gas conduit 14 and the leadline 56.

Operation When it is desired to heat the tubing section 10, gas issupplied from the surface through the tubing 14 and air regulator 16into the inner chamber 12. The gas will gradually escape from thechamber 12 through the restricted apertures 18 where it is ignited bythe igniter 54. It will be apparent that the igniter 54 is operated fromthe surface only when it is desired to ignite the gas escaping from theapertures 18. When the gas escaping from one aperture 18 is ignited, thellame will spread to the remaining apertures in the respective row. Thecombustion of the gas in the chamber 22 will heat the tubing section 10and will also emit heat outwardly through the outer jacket 20 into thesurrounding strata.

The tubing section 10, with the outer jacket 20 and inner jacket 6secured thereto, may be interposed in the tubing string 4 at any desiredheight in the well casing 2. In wells where paratiin contained in thewell uid causes difficulty in the operation of the bottom hole pumpingunit, the tubing section 10 may be disposed below the bottom holepumping unit to heat the well uid owing upwardly therethrough prior toits entrance into the pumping unit. However, in wells where paraffindisposed in the vicinity of the oil producing strata is at asufficiently high temperature to ow readily and not interfere with themoving elements of the pumping unit, but will cool as it is pumpedupwardly through the tubing string 4, the tubing section 10, with itsconnected jackets 20 and 6, may be interposed in the tubing string 4above the bottom hole pumping unit. It will then be apparent that theoil pumped by the pumping unit will be heated by the combustion of gasin the chamber 22 and facilitate the upward tiow of the pumped fluidthrough the tubing string 4.

It will be observed that in any location of the heater, the tubingsection 10 forms a dual function in that it transports the well uid andsimultaneously serves as an element of the heater. The outer jacket 20,being completely closed, permits complete emersion of the heater in welluid contained in the casing 2 without disrupting operation of theheater. It is also to be noted that the lower section 36 of the jacket20 may be removed by unthreading the couplings 42 and 38 to provide-access to the inner jacket 6 for cleaning and repair.

From the foregoing, it is apparent that the present invention provides anovel heater which may be disposed below the bottom hole pumping unit ofa producing oil well to heat the well lluid drawn into the pumping unitand prevent paraffin from clogging or jamming the movable `elements ofthe pumping unit. Also, heat will be emitted into the surrounding stratato enhance the iiow of the well tiuid and increase the production of thepumping unit. It will also be apparent that my novel heater may beinterposed in the tubing string above the pumping unit to facilitateliow of the pumped uid through the tubing string when deemed feasible.Also, the heater may be conveniently operated from the surface of thewell and started or stopped at the will of the operator.

Changes may be made in the `combination and arrangement of parts asheretofore set forth .in the specification and shown in the drawings, itbeing understood Lit) that any modification in the precise embodimentsof the invention may be made within the scope of the following claimswithout departing from the spirit of the invention.

I claim:

1. A gas heater for an oil well having a string of tubing therein,comprising an inner jacket rigidly secured to a section of the tubingand forming an annular chamber around the tubing, said jacket having aplurality of transverse apertures therein, conduit means extendingthrough the well and communicating with the chamber to supply gas to thechamber, an outer jacket surrounding the inner jacket and forming aclosed combustion chamber around the inner jacket and a portion of thetubing, and igniter means carried by the outer jacket arranged to ignitethe gas escaping from said transverse apertures, and vent means forsupplying air to the combustion chamber and discharging fumes therefrom.

2. A gas heater for an oil well having a pumping unit in the lowerportion thereof, comprising a tubing section depending from the pumpingunit and forming an inlet conduit for well tluid, an inner jacketsecured around the tubing section and forming an annular chamber aroundthe tubing, a plurality of restricted transverse apertures in the innerjacket, a gas conduit extending downwardly in the well from the surfaceand communieating with the inner jacket for supplying gas thereto, anouter jacket secured to the well tubing and forming an annular chamberaround the inner jacket and a portion of the tubing, and an ignitercarried by the outer jacket arranged to ignite the gas ejected throughsaid apertures, and vent means for supplying air to the annular chamberand discharging fumes therefrom.

3. A gas heater for an oil well having a string of tubing therein,comprising a housing adapted for tandem connection with the well tubingand .having an inner bore therethrough for the passage of well liuid,tube means extending through the well into the housing, an air regulatoron the lower end of the tube means, a gas chamber around the inner boreand communicating with the air regulator, said gas chamber having aplurality of gas outlets, a combustion chamber in the housingsurrounding the gas chamber and communicating with said outlets, and anigniter in the combustion chamber arranged to ignite gas ejected throughsaid outlets, and means for supplying air to the air regulator andventing fumes from the combustion chamber.

4. A gas heater for an oil well having a string of tubing therein,comprising a housing adapted for tandem connection with the well tubingand having an inner bore therethrough for the passage of well fluid,tube means extending through the well into the housing, an air regulatoron the lower end of the tube means, a gas chamber around the inner boreand communicating with the air regulator, restricted outletscommunicating with the gas chamber, a combustion chamber in the housingsurrounding the gas chamber and communicating with said outlets, anigniter in the combustion chamber arranged to ignite gas ejected throughsaid outlets, an insulated electrical lead line extending lfrom thesurface through the well into connection with the igniter forcontrolling the operation of the ignited, and covered vents extendingupwardly in the well from the combustion chamber to vent off fumes fromthe combustion chamber and supply air to the air regulator.

5. A gas heater for an oil well having a string of tubing therein,comprising an inner jacket rigidly secured to a section of the tubingand forming an annular chamber around the tubing, said jacket having aplurality of transverse apertures therein, `conduit means extendingthrough the well and communicating with the chamber to supply gas to thechamber, an outer ljacket surrounding the inner jacket and forming aclosed combustion chamberarouxd the `inner jacket and 4a portion of thetubing, at least one electrical igniter secured in the wall of the outerjacket and extending into the vicinity of one of said apertures,References Cited inthe le of this patent insulated electrical lead linesextending through the Well UNITED STATES PATENTS from the surface andconnected to the igniter for control- 2,186,035 Niles Jan. 9, 1940

